/* =========================================
   AcousticTrainer PRIR — Arquitectura CSS Moderna
   ========================================= */
@layer base, components, utilities;

@layer base {
  :root {
    color-scheme: dark;
    --bg: #080d1a;
    --panel: #10172a;
    --panel-2: #16203a;
    --panel-3: #1d2949;
    --border: #253459;
    --border-bright: #364d80;
    --text: #e8eefb;
    --muted: #94a3c4;
    --accent: #38bdf8;
    --accent-dim: #0284c7;
    --accent-glow: rgba(56, 189, 248, 0.18);
    --success: #4ade80;
    --warn: #fbbf24;
    --danger: #f87171;
    --purple: #c084fc;
    --knob-bg: #131c33;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 10px 28px -10px rgba(0, 0, 0, 0.65);
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    --font-mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  }

  html, body {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-sans);
    block-size: 100dvh;
    overflow: clip;
  }

  *, *::before, *::after {
    box-sizing: inherit;
  }

  #app {
    block-size: 100dvh;
    display: flex;
    flex-direction: column;
    overflow: clip;
  }
}

@layer components {
  /* ---------------- Header ---------------- */
  .app-header {
    background: var(--panel);
    border-block-end: 1px solid var(--border);
    padding: 8px 18px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    flex-wrap: wrap;
    flex-shrink: 0;
  }

  .header-brand {
    display: flex;
    align-items: center;
    gap: 10px;
  }

  .logo-badge {
    inline-size: 34px;
    block-size: 34px;
    border-radius: 9px;
    background: linear-gradient(135deg, var(--accent-dim), #1e40af);
    border: 1px solid var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 0.85rem;
    color: #fff;
    letter-spacing: 0.04em;
    box-shadow: 0 0 14px var(--accent-glow);
  }

  .app-header h1 {
    margin: 0;
    font-size: 1.05rem;
    font-weight: 700;
    letter-spacing: -0.01em;
  }

  .header-subtitle {
    font-size: 0.72rem;
    color: var(--muted);
  }

  .accent {
    color: var(--accent);
  }

  .header-transport {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
  }

  .ir-source-badge {
    font-size: 0.72rem;
    padding: 4px 9px;
    border-radius: 999px;
    background: var(--panel-2);
    border: 1px solid var(--border);
    color: var(--accent);
    font-weight: 600;
  }

  .ab-segmented {
    display: inline-flex;
    background: #0a1020;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 2px;
    gap: 2px;
  }

  .fader-control {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: #0a1020;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 3px 10px;
    font-size: 0.72rem;
    color: var(--muted);
  }

  .fader-label {
    font-weight: 600;
    color: #94a3b8;
    user-select: none;
  }

  .fader-slider {
    inline-size: 80px;
    block-size: 5px;
    accent-color: var(--primary);
    cursor: pointer;
  }

  .fader-val {
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: 0.7rem;
    font-weight: 700;
    color: #38bdf8;
    min-inline-size: 46px;
    text-align: right;
  }

  .seg-btn {
    border: 0;
    background: transparent;
    color: var(--muted);
    font-size: 0.75rem;
    font-weight: 600;
    padding: 5px 10px;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
  }

  .seg-btn:hover:not(:disabled) {
    color: var(--text);
  }

  .seg-btn.active {
    background: var(--accent-dim);
    color: #fff;
  }

  .header-actions {
    display: flex;
    align-items: center;
    gap: 8px;
  }

  .header-status {
    font-size: 0.72rem;
    padding: 4px 10px;
    border-radius: 999px;
    background: rgba(148, 163, 196, 0.12);
    border: 1px solid var(--border);
    color: var(--muted);
  }

  .header-status.online {
    background: rgba(74, 222, 128, 0.12);
    border-color: rgba(74, 222, 128, 0.4);
    color: var(--success);
  }

  /* ---------------- Navegación de Módulos ---------------- */
  .module-nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    padding: 8px 18px;
    background: #0b1224;
    border-block-end: 1px solid var(--border);
    flex-shrink: 0;
  }

  .nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 14px;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--muted);
    cursor: pointer;
    text-align: start;
    transition: border-color 0.15s, background 0.15s, color 0.15s;
  }

  .nav-item:hover:not(:disabled) {
    border-color: var(--border-bright);
    color: var(--text);
  }

  .nav-item.active {
    background: linear-gradient(90deg, rgba(2, 132, 199, 0.2), rgba(22, 32, 58, 0.9));
    border-color: var(--accent);
    color: var(--text);
    box-shadow: inset 0 0 18px rgba(56, 189, 248, 0.08);
  }

  .nav-dot {
    color: var(--accent);
    font-size: 0.9rem;
  }

  .nav-title {
    font-weight: 700;
    font-size: 0.84rem;
    white-space: nowrap;
  }

  .nav-sub {
    font-size: 0.73rem;
    color: var(--muted);
    overflow: clip;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  /* ---------------- Main Layout ---------------- */
  .app-main {
    flex: 1;
    min-block-size: 0;
    padding: 12px 18px;
    display: flex;
    overflow: clip;
  }

  .view {
    display: none;
    inline-size: 100%;
    block-size: 100%;
    gap: 16px;
    min-block-size: 0;
  }

  .view.active {
    display: grid;
    grid-template-columns: minmax(380px, 46%) 1fr;
  }

  .panel-left,
  .panel-right {
    display: flex;
    flex-direction: column;
    gap: 12px;
    min-block-size: 0;
    overflow-y: auto;
    scrollbar-gutter: stable;
    overscroll-behavior: contain;
    padding-inline-end: 4px;
  }

  /* ---------------- Cards ---------------- */
  .card {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 13px 15px;
    box-shadow: var(--shadow);
  }

  .card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    margin-block-end: 6px;
    flex-wrap: wrap;
  }

  .card h2 {
    margin: 0;
    font-size: 0.92rem;
    font-weight: 700;
    color: var(--text);
  }

  .muted {
    color: var(--muted);
    font-size: 0.77rem;
    line-height: 1.42;
    margin: 0 0 10px 0;
  }

  .muted-xs {
    color: var(--muted);
    font-size: 0.72rem;
  }

  .badge-pill {
    font-size: 0.7rem;
    font-weight: 600;
    padding: 3px 8px;
    border-radius: 999px;
    background: rgba(56, 189, 248, 0.14);
    border: 1px solid rgba(56, 189, 248, 0.35);
    color: var(--accent);
  }

  /* ---------------- Fuente Anecoica & Controles de Audio ---------------- */
  .source-selector-grid {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-block-end: 10px;
  }

  .field-full {
    display: flex;
    flex-direction: column;
    gap: 4px;
  }

  .field-full label {
    font-size: 0.73rem;
    color: var(--muted);
    font-weight: 600;
  }

  .select-input,
  .select-inline {
    background: #0a1020;
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 7px;
    padding: 6px 10px;
    font-size: 0.8rem;
    cursor: pointer;
  }

  .select-inline {
    padding: 3px 8px;
    font-size: 0.73rem;
  }

  .file-dropzone {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    background: rgba(14, 21, 43, 0.75);
    border: 1px dashed var(--border-bright);
    border-radius: 8px;
    cursor: pointer;
    transition: border-color 0.15s, background 0.15s;
  }

  .file-dropzone:hover,
  .file-dropzone.dragover {
    border-color: var(--accent);
    background: rgba(56, 189, 248, 0.08);
  }

  .file-icon {
    font-size: 1.2rem;
  }

  .file-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
  }

  .file-text strong {
    font-size: 0.78rem;
    color: var(--accent);
  }

  .file-text span {
    font-size: 0.7rem;
    color: var(--muted);
  }

  .audio-controls {
    display: flex;
    gap: 8px;
    align-items: center;
    flex-wrap: wrap;
    margin-block-end: 8px;
  }

  /* ---------------- Botones y Toggles ---------------- */
  .btn {
    border: 1px solid var(--border);
    background: var(--panel-2);
    color: var(--text);
    padding: 7px 13px;
    border-radius: 8px;
    font-size: 0.79rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.15s, border-color 0.15s, transform 0.08s;
    display: inline-flex;
    align-items: center;
    gap: 6px;
  }

  .btn:hover:not(:disabled) {
    border-color: var(--accent);
    background: var(--panel-3);
  }

  .btn:active:not(:disabled) {
    transform: translateY(1px);
  }

  .btn:disabled {
    opacity: 0.45;
    cursor: not-allowed;
  }

  .btn-primary {
    background: var(--accent-dim);
    color: #fff;
    border-color: var(--accent);
  }

  .btn-primary:hover:not(:disabled) {
    background: #0369a1;
  }

  .btn-primary.playing {
    background: #15803d;
    border-color: var(--success);
  }

  .btn-secondary {
    background: rgba(56, 189, 248, 0.1);
    color: var(--accent);
    border-color: var(--accent);
  }

  .btn-accent-outline {
    background: rgba(192, 132, 252, 0.12);
    color: var(--purple);
    border-color: rgba(192, 132, 252, 0.5);
  }

  .btn-outline {
    background: transparent;
    color: var(--text);
    border-color: var(--border);
  }

  .btn-ghost {
    background: transparent;
    border-color: transparent;
    color: var(--muted);
  }

  .btn-ghost:hover:not(:disabled) {
    color: var(--text);
    background: var(--panel-2);
  }

  .btn-sm {
    padding: 5px 10px;
    font-size: 0.74rem;
  }

  .btn-xs {
    padding: 4px 8px;
    font-size: 0.71rem;
    border-radius: 6px;
  }

  .checkbox-pill {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    font-size: 0.74rem;
    color: var(--muted);
    background: #0a1020;
    border: 1px solid var(--border);
    padding: 5px 9px;
    border-radius: 7px;
    cursor: pointer;
    user-select: none;
  }

  .checkbox-pill:has(:checked) {
    border-color: rgba(56, 189, 248, 0.55);
    color: var(--text);
    background: rgba(56, 189, 248, 0.1);
  }

  .checkbox-pill input {
    margin: 0;
    accent-color: var(--accent);
  }

  .checkbox-xs {
    padding: 3px 7px;
    font-size: 0.7rem;
  }

  .mini-pills {
    display: inline-flex;
    background: #090e1c;
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 2px;
    gap: 2px;
  }

  .mini-pill {
    border: 0;
    background: transparent;
    color: var(--muted);
    font-size: 0.69rem;
    font-weight: 600;
    padding: 3px 7px;
    border-radius: 4px;
    cursor: pointer;
  }

  .mini-pill:hover:not(:disabled) {
    color: var(--text);
  }

  .mini-pill.active {
    background: var(--accent-dim);
    color: #fff;
  }

  /* ---------------- Medidor y Barra de Carga de IR ---------------- */
  .meter-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-block-end: 8px;
  }

  .meter-track {
    flex: 1;
    block-size: 8px;
    background: #0a1020;
    border-radius: 999px;
    overflow: clip;
    border: 1px solid var(--border);
  }

  .meter-fill {
    block-size: 100%;
    inline-size: 0%;
    background: linear-gradient(90deg, var(--success), var(--accent), var(--warn));
    transition: inline-size 0.08s linear;
  }

  .lufs-readout {
    font-family: var(--font-mono);
    font-size: 0.71rem;
    color: var(--muted);
    white-space: nowrap;
  }

  .ir-loader-bar {
    display: flex;
    align-items: center;
    gap: 6px;
    flex-wrap: wrap;
    padding-block-start: 8px;
    border-block-start: 1px solid rgba(37, 52, 89, 0.6);
  }

  /* ---------------- Perillas PRIR y Sliders ---------------- */
  .knob-stack {
    display: flex;
    flex-direction: column;
    gap: 9px;
  }

  .knob {
    background: var(--knob-bg);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 9px 11px;
    transition: border-color 0.15s, box-shadow 0.15s;
  }

  .knob:has(input[type="range"]:focus-visible),
  .knob.active-knob {
    border-color: var(--accent);
    box-shadow: 0 0 0 1px var(--accent-glow);
  }

  .knob-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    margin-block-end: 4px;
    flex-wrap: wrap;
  }

  .knob-title-group {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
  }

  .knob label {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text);
  }

  .knob-val-group {
    display: flex;
    align-items: center;
    gap: 6px;
  }

  .knob .val {
    font-family: var(--font-mono);
    color: var(--accent);
    font-weight: 700;
    font-size: 0.8rem;
  }

  .jnd-tag {
    font-size: 0.67rem;
    padding: 1px 6px;
    border-radius: 4px;
    background: rgba(148, 163, 196, 0.12);
    color: var(--muted);
    border: 1px solid rgba(148, 163, 196, 0.2);
  }

  .jnd-tag.exceeded {
    background: rgba(74, 222, 128, 0.15);
    color: var(--success);
    border-color: rgba(74, 222, 128, 0.4);
  }

  .knob-scale {
    display: flex;
    justify-content: space-between;
    font-size: 0.66rem;
    color: var(--muted);
    margin-block-start: 2px;
  }

  /* Range Slider Cross-Browser (Modern Web Guidance) */
  input[type="range"] {
    --slider-track-size: 0.42rem;
    --slider-thumb-size: 1.05rem;
    --slider-track-radius: 999px;
    --slider-thumb-radius: 50%;
    --slider-track-color: #223056;
    --slider-fill-color: #38bdf8;
    --slider-thumb-color: #e0f2fe;
    --slider-direction: to right;

    &:dir(rtl) {
      --slider-direction: to left;
    }

    --attr-min: attr(min type(<number>), 0);
    --attr-max: attr(max type(<number>), 100);
    --control-value: attr(value type(<number>), 50);
    --slider-progress: calc(
      progress(var(--control-value), var(--attr-min), var(--attr-max)) * 100%
    );

    appearance: none;
    inline-size: 100%;
    block-size: 1.5rem;
    margin: 0;
    padding: 0;
    border: 0;
    border-radius: 0;
    background: transparent;
    cursor: pointer;
  }

  @supports not (opacity: progress(1, 0, 100)) {
    input[type="range"] {
      --slider-progress: calc(
        (var(--control-value) - var(--attr-min)) /
        (var(--attr-max) - var(--attr-min)) * 100%
      );
    }
  }

  input[type="range"]::-webkit-slider-runnable-track {
    block-size: var(--slider-track-size);
    border: 0;
    border-radius: var(--slider-track-radius);
    background: linear-gradient(
      var(--slider-direction),
      var(--slider-fill-color) var(--slider-progress),
      var(--slider-track-color) var(--slider-progress)
    );
  }

  input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    inline-size: var(--slider-thumb-size);
    block-size: var(--slider-thumb-size);
    margin-block-start: calc(
      (var(--slider-track-size) - var(--slider-thumb-size)) / 2
    );
    border: 2px solid var(--slider-fill-color);
    border-radius: var(--slider-thumb-radius);
    background: var(--slider-thumb-color);
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.5);
  }

  input[type="range"]::-moz-range-track {
    block-size: var(--slider-track-size);
    border: 0;
    border-radius: var(--slider-track-radius);
    background: var(--slider-track-color);
  }

  input[type="range"]::-moz-range-progress {
    block-size: var(--slider-track-size);
    border-radius: var(--slider-track-radius);
    background: var(--slider-fill-color);
  }

  input[type="range"]::-moz-range-thumb {
    inline-size: var(--slider-thumb-size);
    block-size: var(--slider-thumb-size);
    border: 2px solid var(--slider-fill-color);
    border-radius: var(--slider-thumb-radius);
    background: var(--slider-thumb-color);
  }

  input[type="range"]:focus-visible {
    outline: 2px solid var(--slider-fill-color);
    outline-offset: 4px;
  }

  /* ---------------- Métricas ISO 3382 Strip ---------------- */
  .metrics-strip {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(92px, 1fr));
    gap: 8px;
  }

  .metric-box {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 9px;
    padding: 7px 9px;
    display: flex;
    flex-direction: column;
    gap: 2px;
  }

  .metric-box.highlight {
    border-color: var(--accent);
    background: rgba(56, 189, 248, 0.08);
  }

  .m-label {
    font-size: 0.67rem;
    color: var(--muted);
    font-weight: 600;
  }

  .m-val {
    font-family: var(--font-mono);
    font-size: 0.92rem;
    font-weight: 700;
    color: var(--text);
  }

  .m-delta {
    font-size: 0.66rem;
    color: var(--accent);
  }

  /* ---------------- Gráficas IR & EDR ---------------- */
  .ir-card-header {
    align-items: flex-start;
  }

  .ir-subtitle {
    font-size: 0.74rem;
    color: var(--accent);
    margin-block-start: 2px;
  }

  .ir-toolbar {
    display: flex;
    align-items: center;
    gap: 6px;
    flex-wrap: wrap;
  }

  .canvas-wrap {
    position: relative;
    inline-size: 100%;
    background: #070c18;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: clip;
  }

  .ir-card canvas {
    inline-size: 100%;
    block-size: 245px;
    display: block;
  }

  .edr-card canvas {
    inline-size: 100%;
    block-size: 205px;
    display: block;
  }

  .edr-legend,
  .view3d-legend {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-block-start: 7px;
    font-size: 0.7rem;
    color: var(--muted);
  }

  .edr-legend span,
  .view3d-legend span {
    display: inline-flex;
    align-items: center;
    gap: 5px;
  }

  .dot {
    display: inline-block;
    inline-size: 8px;
    block-size: 8px;
    border-radius: 50%;
  }

  .dot-ghost { background: #64748b; }
  .dot-left  { background: #38bdf8; }
  .dot-right { background: #f87171; }
  .dot-itdg  { background: #fbbf24; }
  .dot-c50   { background: #4ade80; }
  .dot-purple{ background: #c084fc; }
  .dot-hot   { background: #f97316; }
  .dot-mid   { background: #22c55e; }
  .dot-cold  { background: #1d4ed8; }

  /* ---------------- Test Adaptativo JND ---------------- */
  .jnd-controls {
    display: flex;
    gap: 6px;
    margin-block-end: 8px;
    flex-wrap: wrap;
  }

  .jnd-feedback {
    font-size: 0.77rem;
    min-block-size: 1.3em;
    margin-block-end: 4px;
    color: var(--warn);
  }

  .jnd-result {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--success);
  }

  .jnd-canvas {
    inline-size: 100%;
    block-size: 76px;
    background: #070c18;
    border: 1px solid var(--border);
    border-radius: 6px;
    margin-block-start: 6px;
    display: block;
  }

  /* ---------------- Módulo 2: Shoebox 3D & Materiales ---------------- */
  .geom-controls {
    display: flex;
    align-items: flex-end;
    gap: 10px;
    flex-wrap: wrap;
    margin-block-end: 10px;
  }

  .field {
    display: flex;
    flex-direction: column;
    gap: 3px;
  }

  .field label {
    font-size: 0.72rem;
    color: var(--muted);
  }

  .field input,
  .sr-inputs input {
    background: #0a1020;
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: 6px;
    padding: 5px 8px;
    font-size: 0.82rem;
    inline-size: 72px;
    font-family: var(--font-mono);
  }

  .geom-summary {
    font-size: 0.75rem;
    font-family: var(--font-mono);
    color: var(--accent);
    background: #0a1020;
    border: 1px solid var(--border);
    padding: 6px 10px;
    border-radius: 6px;
  }

  .sr-positions-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    margin-block-end: 10px;
  }

  .sr-box {
    background: #0b1224;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 7px 9px;
  }

  .sr-title {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--muted);
    margin-block-end: 5px;
    display: flex;
    align-items: center;
    gap: 5px;
  }

  .sr-inputs {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
  }

  .sr-inputs label {
    font-size: 0.7rem;
    color: var(--muted);
    display: flex;
    align-items: center;
    gap: 4px;
  }

  .sr-inputs input {
    inline-size: 54px;
    padding: 3px 5px;
    font-size: 0.76rem;
  }

  .btn-row {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
  }

  .materials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(195px, 1fr));
    gap: 8px;
  }

  .mat-card {
    background: var(--knob-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 8px 10px;
    display: flex;
    flex-direction: column;
    gap: 6px;
  }

  .mat-card-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 6px;
  }

  .mat-face-name {
    font-size: 0.76rem;
    font-weight: 700;
    color: var(--accent);
  }

  .mat-bands-row {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 4px;
    text-align: center;
  }

  .mat-band-col {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
  }

  .mat-band-col span {
    font-size: 0.62rem;
    color: var(--muted);
  }

  .mat-band-col strong {
    font-size: 0.64rem;
    font-family: var(--font-mono);
    color: var(--text);
  }

  .rules-output {
    font-size: 0.78rem;
    color: var(--text);
    line-height: 1.48;
    background: #090f1f;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 10px 12px;
    display: flex;
    flex-direction: column;
    gap: 10px;
  }

  .rule-item {
    border-inline-start: 3px solid var(--accent);
    padding-inline-start: 10px;
  }

  .rule-item ul {
    margin: 4px 0;
    padding-inline-start: 18px;
  }

  .view3d-card {
    display: flex;
    flex-direction: column;
    gap: 8px;
  }

  .view3d-toggles {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
  }

  .view3d {
    block-size: 320px;
    background: radial-gradient(circle at center, #111b36 0%, #070c18 100%);
    border: 1px solid var(--border);
    border-radius: 8px;
    position: relative;
    overflow: clip;
    cursor: grab;
    user-select: none;
  }

  .view3d:active {
    cursor: grabbing;
  }

  .shoebox-scene {
    inline-size: 100%;
    block-size: 100%;
  }

  .metrics3d {
    font-size: 0.76rem;
    color: var(--text);
    background: #090f1f;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 8px 12px;
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: space-between;
  }

  .shoebox-ir-preview canvas {
    inline-size: 100%;
    block-size: 120px;
    background: #070c18;
    border: 1px solid var(--border);
    border-radius: 8px;
    display: block;
  }

  .app-footer {
    background: var(--panel);
    border-block-start: 1px solid var(--border);
    padding: 6px 16px;
    font-size: 0.69rem;
    color: var(--muted);
    text-align: center;
    flex-shrink: 0;
  }

  /* Help button & tooltips */
  .help-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    inline-size: 18px;
    block-size: 18px;
    border-radius: 50%;
    background: rgba(56, 189, 248, 0.1);
    color: var(--primary);
    border: 1px solid rgba(56, 189, 248, 0.3);
    font-size: 0.65rem;
    font-weight: 700;
    cursor: pointer;
    line-height: 1;
    padding: 0;
    transition: background-color 0.15s ease, transform 0.1s ease, border-color 0.15s ease;
    vertical-align: middle;
    margin-inline-start: 4px;
  }

  .help-btn:hover, .help-btn:focus-visible {
    background: var(--primary);
    color: #040915;
    border-color: var(--primary);
    transform: scale(1.1);
    outline: none;
  }

  /* Tooltip hover effect helper */
  [data-tooltip] {
    position: relative;
    cursor: help;
  }

  /* Acoustic Modal Dialog */
  dialog.acoustic-modal {
    margin: auto;
    border: 1px solid #334155;
    border-radius: 14px;
    background: #0b1324;
    color: #f1f5f9;
    padding: 22px 24px;
    max-inline-size: min(560px, 92vw);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.85);
  }

  dialog.acoustic-modal::backdrop {
    background: rgba(3, 7, 18, 0.78);
    backdrop-filter: blur(5px);
  }

  .modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    border-block-end: 1px solid #1e293b;
    padding-block-end: 12px;
    margin-block-end: 14px;
  }

  .modal-title-group h3 {
    margin: 0;
    font-size: 1.05rem;
    font-weight: 700;
    color: #38bdf8;
    display: flex;
    align-items: center;
    gap: 8px;
  }

  .modal-subtitle {
    margin: 2px 0 0 0;
    font-size: 0.75rem;
    color: #94a3b8;
  }

  .modal-close-btn {
    background: transparent;
    border: 1px solid #334155;
    color: #94a3b8;
    font-size: 1.1rem;
    inline-size: 28px;
    block-size: 28px;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.15s ease;
  }

  .modal-close-btn:hover {
    color: #f1f5f9;
    border-color: #64748b;
    background: rgba(255, 255, 255, 0.05);
  }

  .modal-body {
    display: flex;
    flex-direction: column;
    gap: 14px;
    font-size: 0.82rem;
    line-height: 1.5;
    color: #cbd5e1;
  }

  .modal-section-title {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: #94a3b8;
    margin-block-end: 4px;
  }

  .modal-formula {
    background: #060b17;
    border: 1px solid #1e293b;
    border-radius: 8px;
    padding: 10px 14px;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    font-size: 0.82rem;
    color: #38bdf8;
    overflow-x: auto;
  }

  .modal-grid-info {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid #1e293b;
    border-radius: 8px;
    padding: 10px 12px;
  }

  .modal-info-item dt {
    font-size: 0.7rem;
    color: #64748b;
    text-transform: uppercase;
  }

  .modal-info-item dd {
    margin: 2px 0 0 0;
    font-size: 0.8rem;
    font-weight: 600;
    color: #e2e8f0;
  }

  /* Compact EDR Octaves Panel */
  .edr-octaves-panel {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(68px, 1fr));
    gap: 6px;
    margin-block-start: 10px;
    padding-block-start: 8px;
    border-block-start: 1px dashed rgba(255, 255, 255, 0.08);
  }

  .edr-octave-item {
    background: rgba(15, 23, 42, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 6px;
    padding: 5px 6px;
    text-align: center;
    font-size: 0.7rem;
  }

  .edr-octave-freq {
    color: #94a3b8;
    font-size: 0.65rem;
    font-weight: 600;
  }

  .edr-octave-val {
    color: #38bdf8;
    font-family: ui-monospace, monospace;
    font-weight: 700;
    margin-block-start: 2px;
  }

  .edr-octave-bar-bg {
    block-size: 3px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 2px;
    margin-block-start: 4px;
    overflow: hidden;
  }

  .edr-octave-bar-fill {
    block-size: 100%;
    background: var(--primary);
    border-radius: 2px;
  }
}

@layer utilities {
  .hidden {
    display: none !important;
  }

  .sr-only {
    position: absolute;
    inline-size: 1px;
    block-size: 1px;
    padding: 0;
    margin: -1px;
    overflow: clip;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
  }

  @media (max-width: 980px) {
    html, body, #app {
      block-size: auto;
      min-block-size: 100dvh;
      overflow-y: auto;
    }
    .app-main {
      overflow: visible;
    }
    .view.active {
      grid-template-columns: 1fr;
    }
    .panel-left, .panel-right {
      overflow-y: visible;
    }
  }
}